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From: Anton Blanchard <anton@samba.org>
To: Andrew Jones <drjones@redhat.com>
Cc: uobergfe@redhat.com, dzickus@redhat.com,
	akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: Confusing behaviour with /proc/sys/kernel/nmi_watchdog
Date: Wed, 21 Jan 2015 14:39:42 +1100	[thread overview]
Message-ID: <20150121143942.1549e9c9@kryten> (raw)
In-Reply-To: <20141105102645.GA3046@hawk.usersys.redhat.com>

Hi Andrew,

> On Wed, Nov 05, 2014 at 09:34:20AM +1100, Anton Blanchard wrote:
> > commit 9919e39a1738 ("kvm: ensure hard lockup detection is disabled
> > by default") provided a way for the kernel to disable the hard
> > lockup detector at runtime.
> > 
> > I'm using it on ppc64 but notice some weird behaviour with the
> > nmi_watchdog procfs variable. At boot, that the hard lockup
> > detector appears to be enabled even when we disable it via
> > watchdog_enable_hardlockup_detector(false):
> > 
> > # cat /proc/sys/kernel/nmi_watchdog 
> > 1
> > 
> > I have to echo 0 to it then echo 1 again to enable it.
> > 
> > Anton
> 
> Hi Anton,
> 
> Yes, the nmi watchdog proc variables are currently a bit
> confusing. Uli has posted a series to clear all that up
> though. Please see
> 
> https://lkml.org/lkml/2014/10/17/340

Any progress on this? I'm rebasing our hardware NMI patch for ppc64 and
notice the strange behaviour is still in mainline.

Anton

  reply	other threads:[~2015-01-21  3:39 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-04 22:34 Anton Blanchard
2014-11-05 10:26 ` Andrew Jones
2015-01-21  3:39   ` Anton Blanchard [this message]
2015-01-21 10:52     ` Andrew Jones
2015-01-21 14:30       ` Don Zickus
2014-11-05 14:53 ` Don Zickus
2014-11-05 18:53   ` Anton Blanchard

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